<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Issue 64: Exception handling in basic_istream::operator&gt;&gt;(basic_streambuf*)</title>
<meta property="og:title" content="Issue 64: Exception handling in basic_istream::operator&gt;&gt;(basic_streambuf*)">
<meta property="og:description" content="C++ library issue. Status: TC1">
<meta property="og:url" content="https://cplusplus.github.io/LWG/issue64.html">
<meta property="og:type" content="website">
<meta property="og:image" content="http://cplusplus.github.io/LWG/images/cpp_logo.png">
<meta property="og:image:alt" content="C++ logo">
<style>
  p {text-align:justify}
  li {text-align:justify}
  pre code.backtick::before { content: "`" }
  pre code.backtick::after { content: "`" }
  blockquote.note
  {
    background-color:#E0E0E0;
    padding-left: 15px;
    padding-right: 15px;
    padding-top: 1px;
    padding-bottom: 1px;
  }
  ins {background-color:#A0FFA0}
  del {background-color:#FFA0A0}
  table.issues-index { border: 1px solid; border-collapse: collapse; }
  table.issues-index th { text-align: center; padding: 4px; border: 1px solid; }
  table.issues-index td { padding: 4px; border: 1px solid; }
  table.issues-index td:nth-child(1) { text-align: right; }
  table.issues-index td:nth-child(2) { text-align: left; }
  table.issues-index td:nth-child(3) { text-align: left; }
  table.issues-index td:nth-child(4) { text-align: left; }
  table.issues-index td:nth-child(5) { text-align: center; }
  table.issues-index td:nth-child(6) { text-align: center; }
  table.issues-index td:nth-child(7) { text-align: left; }
  table.issues-index td:nth-child(5) span.no-pr { color: red; }
  @media (prefers-color-scheme: dark) {
     html {
        color: #ddd;
        background-color: black;
     }
     ins {
        background-color: #225522
     }
     del {
        background-color: #662222
     }
     a {
        color: #6af
     }
     a:visited {
        color: #6af
     }
     blockquote.note
     {
        background-color: rgba(255, 255, 255, .10)
     }
  }
</style>
</head>
<body>
<hr>
<p><em>This page is a snapshot from the LWG issues list, see the <a href="lwg-active.html">Library Active Issues List</a> for more information and the meaning of <a href="lwg-active.html#TC1">TC1</a> status.</em></p>
<h3 id="64"><a href="lwg-defects.html#64">64</a>. Exception handling in <code>basic_istream::operator&gt;&gt;(basic_streambuf*)</code></h3>
<p><b>Section:</b> 31.7.5.3.3 <a href="https://wg21.link/istream.extractors">[istream.extractors]</a> <b>Status:</b> <a href="lwg-active.html#TC1">TC1</a>
 <b>Submitter:</b> Matt Austern <b>Opened:</b> 1998-08-11 <b>Last modified:</b> 2017-04-22</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all other</b> <a href="lwg-index.html#istream.extractors">issues</a> in [istream.extractors].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#TC1">TC1</a> status.</p>
<p><b>Discussion:</b></p>
<p>27.6.1.2.3, paragraph 13, is ambiguous. It can be interpreted two
different ways, depending on whether the second sentence is read as an
elaboration of the first. </p>


<p id="res-64"><b>Proposed resolution:</b></p>
<p>Replace  [istream::extractors], paragraph 13, which begins
&quot;If the function inserts no characters ...&quot; with:</p>

<blockquote>
  <p>If the function inserts no characters, it calls
  <code>setstate(failbit)</code>, which may throw
  <code>ios_base::failure</code> (27.4.4.3). If it inserted no characters
  because it caught an exception thrown while extracting characters
  from <code>sb</code> and <code>failbit</code> is on in <code>exceptions()</code>
  (27.4.4.3), then the caught exception is rethrown. </p>
</blockquote>





</body>
</html>
